/*
 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
 *           (C) 2000 Antti Koivisto (koivisto@kde.org)
 *           (C) 2000 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2003, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_STYLE_BORDER_VALUE_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_STYLE_BORDER_VALUE_H_

#include "third_party/blink/renderer/core/css/style_color.h"
#include "third_party/blink/renderer/core/style/computed_style_constants.h"
#include "third_party/blink/renderer/platform/geometry/layout_unit.h"
#include "third_party/blink/renderer/platform/graphics/color.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"

namespace blink {

class BorderValue {
  DISALLOW_NEW();
  friend class ComputedStyle;

 public:
  BorderValue() : style_(static_cast<unsigned>(EBorderStyle::kNone)) {
    SetWidth(LayoutUnit(3));
  }

  BorderValue(EBorderStyle style, const StyleColor& color, LayoutUnit width) {
    SetColor(color);
    SetStyle(style);
    SetWidth(width);
  }

  bool operator==(const BorderValue& o) const {
    return width_ == o.width_ && style_ == o.style_ && color_ == o.color_;
  }

  // The default width is 3px, but if the style is none we compute a value of 0
  // (in ComputedStyle itself)
  bool VisuallyEqual(const BorderValue& o) const {
    if (style_ == static_cast<unsigned>(EBorderStyle::kNone) &&
        o.style_ == static_cast<unsigned>(EBorderStyle::kNone))
      return true;
    if (style_ == static_cast<unsigned>(EBorderStyle::kHidden) &&
        o.style_ == static_cast<unsigned>(EBorderStyle::kHidden))
      return true;
    return *this == o;
  }

  bool operator!=(const BorderValue& o) const { return !(*this == o); }

  void SetColor(const StyleColor& color) { color_ = color; }

  StyleColor GetColor() const { return color_; }

  LayoutUnit Width() const { return LayoutUnit::FromRawValue(width_); }
  void SetWidth(LayoutUnit width) { width_ = ClampToLimitedWidth(width); }

  // Since precision is lost with fixed point, comparisons also have
  // to be done in fixed point.
  bool WidthEquals(LayoutUnit width) const { return width == Width(); }

  EBorderStyle Style() const { return static_cast<EBorderStyle>(style_); }
  void SetStyle(EBorderStyle style) { style_ = static_cast<unsigned>(style); }

  static LayoutUnit MaxWidth() { return LayoutUnit::FromRawValue(kMaxValue); }

 protected:
  // In order to conserve memory, the border width uses fixed point, which can
  // be bitpacked. This fixed point implementation is essentially the same as in
  // LayoutUnit. Six bits are used for the fraction, which leaves 20 bits for
  // the integer part, making 1048575.98 the largest number.
  static constexpr int kMaxValue = (1 << 26) - 1;

  static unsigned ClampToLimitedWidth(LayoutUnit width) {
    DCHECK_GE(width, 0);
    // Avoid min()/max() from std here in the header, because that would require
    // inclusion of <algorithm>, which is slow to compile.
    int raw_width = width.RawValue();
    if (raw_width > kMaxValue)
      raw_width = kMaxValue;
    return static_cast<unsigned>(raw_width);
  }

  StyleColor color_;

  unsigned width_ : 26;  // Fixed point width
  unsigned style_ : 4;   // EBorderStyle
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_STYLE_BORDER_VALUE_H_
